The present invention relates in general to vehicular friction clutch and transmission structures and in particular to an improved clutch brake which is adapted for use in such a structure. The present invention also relates to an improved method for manufacturing the clutch brake.
In vehicular drive trains, it is well known to utilize a friction clutch to temporarily disconnect an engine from a transmission in order to permit the transmission to perform a gear shifting operation. Prior to such a gear shifting operation, gears to be mated together within the transmission are driven by the engine at different rotational speeds. The clutch is disengaged so that the mating gears are not continued to be driven by the engine and, therefore, can be aligned with one another prior to the gear shifting operation. This pre-shifting alignment prevents undesirable clashing of the gear teeth. However, in a non-synchronized transmission, the input shaft to the transmission (which is the output shaft from the clutch) continues to rotate for a period of time after the clutch has been disengaged because of momentum. Accordingly, in such non-synchronized transmissions, it is necessary to provide some means for slowing or stopping the rotation of the input shaft to the transmission when the clutch is disengaged to permit the alignment of the gears as described above.
The clutch brake is a device which is well known in the art for slowing or stopping the rotation of the input shaft to the transmission when the clutch is disengaged. The clutch brake is disposed about the input shaft between the rearward end of the clutch and the forward end of the transmission. The clutch brake is mounted on the input shaft for rotation therewith. Limited axial movement of the clutch brake along the input shaft, however, is permitted. A release mechanism of the clutch is also slidably mounted about the input shaft for limited axial movement. The release mechanism is movable between engaged and disengaged positions for selectively connecting and disconnecting the input shaft to the engine. When moved to the disengaged position, the release mechanism slides rearwardly toward the forward end of the transmission. Such movement causes the clutch brake to be frictionally engaged between the release mechanism of the clutch and the forward end of the transmission. As a result, rotation of the clutch brake, as well as of the input shaft to the transmission, is slowed or stopped.
In the past, clutch brakes of the type described above have been formed having a pair of opposed metallic covers adapted to respectively engage the release mechanism of the clutch and the forward end of the transmission. Each of the covers included an annular strip of fibrous friction facing material adhered thereto. Such friction facings were subject to wear resulting from heat build-up and repetitive usage during the frictional engagement described above. Accordingly, it would be desirable to provide an improved clutch brake which overcomes these drawbacks.